Transcript Analytical and Chromatography - Sigma

Hypothetical Model on the Functions of the WRN, BLM and MRE11
sigma-aldrich.com/cellsignaling
Hypothetical Model on the Functions of the WRN, BLM and
MRE11
• WRN and BLM are genes encoding DNA helicases mutated in the human progeria
syndromes: Werner and Bloom Syndromes. MRE11 complex is mutated in genetic
instability syndromes: Nijmegen breakage syndrome and ataxia telangiectasia-like
disorder. All three may be involved in the resolution of a stalled replication fork and
in checkpoint signaling during S phase. DNA replication fork stalling results in the
formation of abnormal structures and occurs at frequencies sufficient to be a
significant source of endogenous DNA damage. BLM may be recruited to these
sites resulting in its phosphorylation by ataxia telangiectasia mutated proteinrelated protein (ATR). The activated or phosphorylated BLM determines the
proper recruitment of the MRE11 complex. WRN may be required at this point to
provide endonuclease or helicase activity. Also at this stage, WRN may be
phosphorylated by ATR or by MRE11 and NBS1, resulting in checkpoint
reinforcement. Replication recovery can also involve homologous recombination
(HR) and BRCA1 and RAD51.
Adapted from Franchitto A. et al, Human Molecular Genetics 11:2447, 2002.
sigma-aldrich.com/cellsignaling
mRNP Transport through the Nuclear Pore Complex (NPC)
sigma-aldrich.com/cellsignaling
Cargo Import by the Importin-Importin Pathway
sigma-aldrich.com/cellsignaling
Modular Structure of Transcription Factors
sigma-aldrich.com/cellsignaling
Transcription Activation by Nuclear Receptors [1 of 2]
sigma-aldrich.com/cellsignaling
Transcription Activation by Nuclear Receptors [2 of 2]
sigma-aldrich.com/cellsignaling
Coupled RNA Splicing and Nuclear Export
sigma-aldrich.com/cellsignaling
RNA Polyadenylation
sigma-aldrich.com/cellsignaling
Mammalian mRNA Polyadenylation Machinery
sigma-aldrich.com/cellsignaling
RNA Maturation
sigma-aldrich.com/cellsignaling
RNA-guided Epigenetic Control of Gene Expression
sigma-aldrich.com/cellsignaling
Phosphorylation-driven Regulatory Switch
from Transcription Initiation to Elongation
sigma-aldrich.com/cellsignaling